A 38-year-old gentleman reports of decreased hearing in the right ear for the last 2 years. On testing with a 512-Hz tuning fork, the Rinne's test (without masking) is negative on the right ear and positive on the left ear. With the Weber's test the tone is perceived louder in the left ear. The patient most likely has:

Negative Rinne on the right means bone conduction better than air conduction, meaning thereby conductive deafness. But this test has been done without masking the left ear which is normal in this case. Response to bone conduction could be from the left ear. Thus right ear suffers from sensorineural deafness. Rinne's test in this case is "false negative".